Now, I believe that it would be fairly simple to moderate difficulty...
What I wanted, but couldn't find was a script that would, when used in conjunction with an added-features script (like the options for endgame script, or the vampyr key item script) would create a sub-menu. What I mean by this, is that, in the case of the vampyr key item script, if you click on Item, it calls up the next menu.
The next menu will look like the item menu you would normally see, but you can also see two options at the top; one is Items, the other is Key Items....
This style of menus is used in most, if not all of the final fantasies, ranging back, at the very least, to FF3, where it stored items like Terra's Pendant (or am I thinking of, CT and Marle's Pendant?), Fish for Cid, and one-of-a-kind items that were of some great importance or significance.
I figured that this would look nicer than the setup that there is now, especially if you plan on adding several features, and it has very close to unlimited range if it is made correctly...